Microfeature Fabrication in Brittle Materials Using Rotary Ultrasonic Micro-Machining

脆性材料的微特征制造(包括微钻孔、微槽和微纹理)已被用于各种应用，如用于压力和流量传感器和太阳能电池板的硅晶片/面板的微钻孔，牙科和整形外科的微钻孔，航空发动机高温陶瓷燃料喷嘴的微加工，以及透镜和光纤等光学部件的微特征。这些材料的脆性使得它们很难用传统的机械加工工艺进行加工，这可能会导致切屑和断裂。热加工和化学非传统加工(NTM)工艺也被应用于微机械加工。然而，NTM可能会导致不需要的材料氧化和热影响区，可能具有较低的加工效率，并且可能需要化学处理。需要一种高效率、高性价比、高质量的脆性材料微加工工艺。该奖项支持使用旋转超声微加工(RUµM)制造脆性材料微特征的基础研究。有关RU？M工艺的许多知识空白阻碍了其今天的广泛使用。这项研究将填补一些知识空白，并可能对电子、医疗、航空航天、光学设备和其他高科技行业产生重大影响。研究成果有助于降低制造成本和消除化学物质的使用，具有广泛的环境、经济和社会效益。本项目的研究目标是对旋转超声微加工中刀具和工件的行为有一个基本的了解，以便能够对脆性材料进行有效、高效和高质量的微特征机械磨削。研究目的是在超声振动的辅助下，通过磨料与工件之间的相互作用，揭示材料去除、切削力产生、表面形成和质量的机理。该项目的成功完成将具体产生关于以下方面的知识：(1)不同加工变量下不同刀具磨料几何形状的材料断裂和去除机理；(2)单个磨粒与工件通过超声振动在微观尺度上相互作用产生切削力的机理；(3)不同超声振动条件下的表面形成和材料去除过程中产生的表面建模。本科生和研究生，包括那些来自代表不足的群体的学生，都将参与进行实验和分析结果。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Microfeature fabrication (including micro-drilling, micro-grooving, and micro-texturing) of brittle materials has been used in a variety of applications, such as the micro-drilling of silicon wafers/panels for use in pressure and flow sensors and solar panels, micro-drilling in dentistry and orthopedic surgeries, micro-machining of high-temperature ceramic fuel nozzles for aerospace engines, and micro-featuring of optical components like lenses and fibers. The brittleness of these materials makes them difficult to be machined using conventional mechanical processes, which can cause chipping and fracture. Thermal and chemical non-traditional machining (NTM) processes have also been applied for micro-machining. However, NTM can cause unwanted material oxidation and heat-affected zones, can have poor machining efficiency and can require chemical use. A high-efficiency, cost-effective, and high-quality micro-fabrication process for brittle materials is needed. This award supports fundamental research in microfeature fabrication in brittle materials using rotary ultrasonic micro-machining (RUµM). Many knowledge gaps on the RUµM process prevent its widespread use today. The research will fill some of the knowledge gaps and could have significant impacts on electronic, medical, aerospace, optical device, and other high-tech industries. Research results can help reducing manufacturing cost and eliminate chemical usage, which would benefit the environment, economy, and society in general.The research goal of this project is to generate fundamental understanding of tool and workpiece behavior in rotary ultrasonic micro-machining to enable an effective, efficient, and high-quality microfeature mechanical grinding process for brittle materials. The research objective is to discover the mechanisms of material removal, cutting force generation, and surface formation and quality through the interactions between abrasive and workpiece with the assistance of ultrasonic vibration. The successful completion of this project will specifically generate knowledge on (1) material fracture and removal mechanisms for different tool abrasive geometries under different machining variables, (2) cutting force generation mechanisms through single abrasive particle-workpiece interactions at the microscale with ultrasonic vibration, and (3) surface formation under different ultrasonic vibration conditions and modeling of surfaces which result from the material removal processes. Both undergraduate and graduate students, including those from the underrepresented groups, will be involved in conducting experiments and analyzing results.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.